Light-sensitive material

ABSTRACT

EACH OF R1 AND R2 IS A LOWER ALKYL GROUP, A BENZYL GROUP, OR A PHENYL GROUP, R3 IS A LOER ALKYL GROUP, A PHENYL GROUP, OR A BENZYL GROUP, R4 IS ALKOXY OR AN AMINO GROUP, R5 IS HYDROGEN, A LOWER ALKYL GROUP, A PHENYL GROUP OR A BENZYL GROUP, R6 IS LOWER ALKYL, EACH OF Z1 AND Z2 REPRESENTS THE NON-METALLIC ATOMS NECESSARY TO COMPLETE THE SAME OR DIFFERENT THIAZOLE NUCLEUS, BENZOTHIAZOLE NUCLEUS, NAPTHOTHIAZOLE NUCLEUS, SELENAZOLE NUCLEUS, BENZOSELENAZOLE NUCLEUS, OR NAPHTHOSELENAZOLE NUCLEUS, EACH OF Q1 AND Q2 IS SULPHUR OR SELENIUM, EACH OF A AND B IS HYDROGEN, A FUSED AROMATIC RING, TETRAMETHYLENE, METHYLENE DIOXY OR ONE OR MORE SUBSTITUENTS SELECTED FROM LOWER ALKYL, PHENYL, ALKOXY, LOWER ALKYLTHIO, HALOGEN AND HYDROXYL, AND X-IS AN ANION WHEN ONE OF R1 AND R2 DOES NOT CONTAIN AN ANIONIC GROUP.   (II) ((-Q1-(1,2-PHENYLENE(-A1))-N(-R1)(+)=)&gt;C-CH=C(R6)-CH=C&lt;(-Q1-(1,2-PHENYLENE( -B))-N(-R2)-)) X(-) WHEREIN:   PANCHROMATIC LIGHT-SENSTITIVE SILVER HALIDE EMULSIONS ARE PROVIDE, THE SENSITIVITY OF WHICH EXTENDS UP TO THE EXTREME RED (OR NEAR INFRARED) REGION OF THE SPECTRUM BY INCORPORATING INTO SAID EMULSIONS A RHODACARBOCYANINE WHOSE SENSITIZING ACTIVITY EXTENDS BEYOND 700 NM. AND WHICH CORRESPONDS TO THE FOLLOWING GENERAL FORMULA 1 AND AT LEAST ONE CARBOCYANINE CORRESPONDING TO FOLLOWING GENERAL FORMULA II: (I) ((=N(-R2)-Z2-)&gt;C-CH=C(-R4)-CH=,3-R3,5-(=N(-R1)-Z1-)&gt;C= CH-C(-R5)=THIAZOLIN-4-ONE)(+) X(-)

1971 H. A. PHILIPPAERTS ETA!- 3,600,183

LIGHT-SENSITIVE MATERIAL Filed Nov. 8, 1968 2 Sheets-Sheet 1 FIG] F IG..?

FIG. 3

l f i FIG. 4 I fx FIG. 5

FIG. 7

United States Patent Ofice:

Int. Cl. G03c 1/28 US. Cl. 96-123 3 Claims ABSTRACT OF THE DISCLOSURE Panchromatic light-sensitive silver halide emulsions are provide, the sensitivity of which extends up to the extreme red (or near infrared) region of the spectrum by incorporating into said emulsions a rhodacarbocyanine whose sensitizing activity extends beyond 700 nm. and which corresponds to the following general Formula I and at least one carbocyanine corresponding to following general Formula II:

each of R and R is a lower alkyl group, a benzyl group,

or a phenyl group,

R is a lower alkyl group, a phenyl group, or a benzyl R is alkoxy or an amino group,

R is hydrogen, a lower alkyl group, a phenyl group or a benzyl group,

R is lower alkyl,

each of Z and Z represents the non-metallic atoms necessary to complete the same or different thiazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, selenazole nucleus, benzoselenazole nucleus, or naphthoselenazole nucleus,

each of Q and Q is sulphur or selenium,

each of A and B is hydrogen, a fused aromatic ring, tetramethylene, methylene dioxy or one or more substituents selected from lower alkyl, phenyl, alkoxy, lower alkylthio, halogen and hydroxyl, and

X- is an anion when one of R and R does not contain an anionic group.

The present invention relates to photographic materials comprising at least one light-sensitive silver halide emulsion, the optical sensitivity of which extends to the extreme red region of the spectrum, More particularly, the present invention relates to photographic silver halide materials with camera-speed having a homogeneous and uniform spectral sensitivity extending from the green over the yellow and red to the near infrared region of the spectrum.

Photographic materials with camera speed having a uniform spectral sensitivity extending from the green to the near infrared region of the spectrum may be of importance for aerial photography.

3,60,183 Patented Aug. 1?, 1971 It is known to extend the natural spectral sensitivity of photographic silver halide emulsions to the green, yellow and red region of the spectrum by incorporating therein appropriate optical sensitizers belonging to the class of the cyanine dyes. Panchromatic silver halide emulsions for common image photography have a sensitizing action not extending beyond 700 nm.

The sensitization of photographic silver halide emulsions with camera-speed in the deep-red region lying between 700 nm. and about 760 nm. for obtaining lightsensitive materials having a uniform sensitivity from the green to the far red region or near infrared region of the spectrum, poses a number of difiiculties. Indeed various sensitizing dyes are known for this spectral region e..g. pentamethine dyes, heptamethine dyes, tetramethine merocyanine dyes, and rhodacyanine dyes, but most of these dyes have serious disadvantages when used for sensitizing highly sensitive silver bromoiodide or bromochloroiodide emulsions with camera speed.

The pentaand heptamethine dyes are unsuitable for use in combination with other sensitizers for the shorter wavelength regions in order to obtain a photographic silver halide material witlh camera-speed having a spectral sensitivity as described above because, in photographic materials with camera-speed, they generally have too low a sensitizing action in the said deep-red region, give rise to fog easily and are insufliciently stable on storing.

The teramethine merocyanine and rhodacyanine dyes, are also unsuitable for use in combination with sensitizers for the shorter wavelength regions in order to provide photographic materials of the kind described above because in photographic materials with camera-speed they give rise to a loss in the intrinsic sensitivity of the emulsion and also have too low a sensitizing action in the deep-red region of the spectrum.

In accordance with the present invention rhodacarbocyanines are provided which lend themselves perfectly, without giving rise to desensitization, for application in photographic materials with camera-speed in combination with sensitizers for the green and red region of the spectrum in order to obtain a uniform spectral sensitivity extending from the green region over the yellow and red region to the extreme red region of the spectrum.

More particularly, according to the present invention panchromatic light-sensitive silver halide emulsions are provided, the sensitivity of which extends up to the extreme red (or near infrared) region of the spectrum by incorporation into said emulsions a rhodacarbocyanine whose sensitizing activity extends beyond 700 nm. and which corresponds to the following general Formula I and at least one carbocyanine corresponding to following general Formula II:

Each of R and R represents a substituent of the type contained in cyanine dyes on the cyanine nitrogen atom, e.g. an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl including a substituted alkyl group such as ,B-hydroxyethyl, [i-acetoxyethyl, carboxymethyl and carboxyethyl as described in the German patent specification 704,141, sulphoalkyl as described in the United Kingdom patent specification 742,112 such as sulphoethyl, sulphopropyl, sulphobutyl, sulphatoalkyl as described in the French patent specification 1,149,769 such as sulphatopropyl and sulphatobutyl, the group ACOO-BSO OH wherein A and B have the same significance as set forth in United Kingdom patent specification 886,271 such as a sulphocarbomethoxymethyl group, an w-sulphocarbopropoxymethyl group, an w-sulphocarbobutoxyrnethyl group, a p-(w-sulphocarbobutoxy)-benzyl group, the group -AWNH-V-B wherein A, W, V and B have the same significance as set forth in United Kingdom patent specification 904,332 such as an N-(methylsulphonyl)-carbamylmethyl group, 7- (acetylsulphamyl)-propyl, a 6 (acetylsulphamyl) butyl group, the group wherein A has the same significance as described in the United Kingdom patent specification 886,270, an aralkyl group such as a benzyl group including a substituted aralkyl group such as carboxybenzyl and sulphobenzyl, an aryl group such as phenyl including a substituted aryl group such as carboxyphenyl, a cycloalkyl group such as cyclohexyl or an allyl group,

R stands for alkyl such as ethyl including substituted alkyl such as B-sulphoethyl, fl-aminoethyl, aralkyl such as benzyl including substituted aralk'yl such as carboxybenzyl, aryl such as phenyl including substituted aryl such as p-carboxyphenyl and allyl,

R represents an alkoxy group such as methoxy, an amino group or a substituted amino group such as anilino and N-methyl-N-acetyl-amino,

R stands for hydrogen, alkyl including substituted alkyl, aralkyl including substituted aralkyl, or aryl including substituted aryl,

Each of Z and Z represents the non-metallic atoms necessary to complete the same or different heterocyclic nucleus of the thiazole series (e.g. thiazole, 4-methylthiazole, 4-phenylthiazole, S-methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2- thienyl)-thiazole), those of the benzothiazole series (e.g. benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-ch1orobenzothiazole, 4- methyl-benzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole, S-phenylbenzothiazole, 4- methoxybenzothiazole, S-methoxybenzothiazole, 6-n1ethoxybenzothiazole, S-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, 4,5, 6,7-tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylene benzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, 5,6-dimethylbenzothiazole), those of the naphthothiazole series (e.g. naphtho[2,1-d] thiazole, naphtho l ,2-d] thiazole, S-methoxynaphtho 1,2- d]thiazole, 5-ethoxynaphtho[1,2-d]thiazole, 8-methoxynaphtho[2,l d]thiazole, 7-methoxynaphtho[2,l d]thiazole), those of the thionaphtheno[7,6-d]thiazole series (e.g. 7-methoxythionaphtheno[7,6-d]thiazo1e), those of the selenazole series (e.g. 4-methylselenazole, 4-phenylselenazole), those of the benzoselenazole series (e.g. benzoselenazole, S-chlorobenzoselenazole, 5-methyl-6-methoxy-benzoselenazole, S-methylbenzoselenazole, 5,6-dimethylbenzoselenazole, S-methoxybenzoselenazole, 5-hydroxybenzoselenazole, 4,5,6,7-tetrahydrobenzoselenazole, 5,6-dioxymethylene-benzoselenazole), those of the naphthoselenazole series (e.g. naphtho[2,1- d]selenazole, naphtho[1,2-d]selenazole),

X- represents an acid radical such as a chloride ion, a bromide ion, an iodide ion, a perchlorate ion, a benzene sulphonate ion, a p-toluenesulphonate ion, a methylsulphate ion, an ethylsulphate ion, a propylsulphate ion, but X- is not present when one of R and R contains an anionic group, e.g.

R R and X- have the same significance as above,

R stands for alkyl preferably having at most 5 carbon atoms, e.g. methyl and ethyl,

Each of Q and Q (the same or different) stands for sulphur or selenium, and

Each of A and B (the same or different) represents a hydrogen atom, a fused benzene ring, a tetramethylene group, a methylene dioxy group or one or more substituents selected from alkyl such as methyl, aryl such as phenyl, alkoxy such as methoxy, alkylthio such as methylthio, halogen such as fluorine, chlorine, iodine and bromine and hydroxyl.

The sensitizers of general Formulae I and II are completely compatible with each other; hence, emulsions containing these combinations of sensitizers have a broad uniform spectral sensitivity extending from the blue to the extreme red region of the spectrum. As is illustrated hereinafter, the rhodacarbocyanines corresponding to general Formula I can be used in combination with carbocyanines corresponding to general Formula II without giving rise to desensitization; on the contrary, in some cases even a slight increase in the general sensitivity is obtained. Moreover, the rhodacarbocyanines show the advantage of having no fogging action on photographic silver halide emulsions. In addition thereto, with the combination of sensitizers of use according to the present invention a practically uniform gamma-value is obtained for the whole region of the spectral sensitization.

The rhodacarbocyanines corresponding to general Formula I and the carbocyanines corresponding to general Formula II may be prepared by any of the methods known in cyanine dye chemistry.

Rhodacarbocyanines falling within the ambit of the above general Formula I and suitable for use according to the present invention are described in United Kingdom patent specifications 646,137 and 837,674 and in Belgian patent specification 532,028. The following are more specific examples of such rhodacarbocyanines.

CH -C O-N-s Oz-CHS $3H5 The combination of sensitizing dyes, according to the present invention may be used for extending the spectral sensitivity of various kinds of photographic emulsions. Various silver salts may be used as the sensitive salt such as silver chloride, silver bromide, silver iodide or mixed silver halides such as silver chlorobromide, silver bromoiodide and silver chlorobromoiodide. The hydrophilic col loid used as the vehicle for the silver halide may be for example gelatin, agar-agar, zein, collodion, water-soluble cellulose derivatives such as carboxymethyl cellulose, polyvinyl alcohol, poly-N-vinyl pyrrolidinone or other hydrophilic synthetic or natural resins or polymeric compounds gelatin being however favoured.

To prepare photographic emulsions sensitized according to the invention the dyes are incorporated in the photographic emulsion by one of the methods customarily employed in the art for incorporating photographic ingredients into hydrophilic colloid compositions. In practice it is convenient to dissolve the dyes in an appropriate watermiscible or water-immiscible high-boiling or low-boiling organic solvent or a mixture thereof and to disperse the solution obtained occasionally in the presence of a dispersing agent in a composition of a hydrophilic colloid forming or forming part of the binding agent of the photographic light-sensitive emulsion. This composition may be the photographic emulsion itself ready for coating or a mere aqueous non-light-sensitive hydrophilic colloid solution which, after the occasional removal of the solvents employed, is intimately mixed at the appropriate moment with the coating composition of the lightsensitive emulsion. For more details about particular suitable dispersing techniques that can be employed for incorporating the above sensitizers in photographic emulsions there can be referred amongst others to United States patent specification 2,304,940, United Kingdom patent specifications 791,219, 1,099,414, 1,099,415, 1,099,416, 1,099,417, 1,- 098,594 and Belgian patent specifications 682,413 and 705,889.

Another interesting technique for dispersing sensitizing dyes in silver halide emulsions consists in dispersing the dye in the presence of a dispersing agent in an aqueous gelatin solution and admixing the resulting gelatin dispersion at the appropriate moment with a silver halide emulsion before coating of the latter. This technique can be illustrated as follows: 100 mg. of sensitizing dye and 250 mg. of the sodium salt of oleyl methyl ta-uride are ground, 'for 36 hours in the presence of 100' ml. of a 2% aqueous solution of gelatin, in aswinging mill.

The sensitizing dyes of use according to the invention can be incorporated at any stage of emulsion preparation and should be uniformly distributed throughout the emulsion. They are preferably incorporated after the chemical ripening and just before coating.

The concentration in the emulsion of the rhodacarbocyanine of general Formula I and of the carbocyanine of general Formula II each taken separately can vary between wide limits, for example from mg. to 1 g. and preferably from to 300 mg. per mole of silver halide and will vary according to the kind of emulsion, the sensitizing effect desired, etc. The suitable and most economical concentration for any given emulsion will be apparent to those skilled in the art, upon making the ordinary tests and observations customary in the art of emulsion making.

The dyes are preferably incorporated into photographic emulsions the general sensitivity of which has been increased by physical and chemical ripening. These emulsions may be chemically sensitized by effecting the ripening in the presence of small amounts of sulphur containing compounds such as allyl isothiocyanate, allyl thiourea, sodium thiosulphate, potassium selenocyanide, etc. The emulsions may also be sensitized by means of reducing sensitizers such as tin compounds, imino-aminomethane-sulphinic acids and the derivatives thereof, cadmium salts, and the salts of noble metals such as gold, platinum, palladium, iridium, ruthenium and rhodium.

In preparing the photographic emulsions according to the invention the usual and suitable addenda such as antifoggants, stabilizers, development accelerators, plasticizers, wetting agents and hardeners are also incorporated into the emulsion in a known manner.

Suitable hardening agents are amongst others formaldehyde, halogen-substituted aldehydes comprisign a carboxyl group such as mucobromic acid, diketones, dialdehydes, etc.

Compounds suitable for sensitizing the emulsions by development are e.g. compounds of the polyoxalkylene type such as alkylene oxide condensation products as described amongst others in United States patent specifications 2,531,832 and 2,533,990, in United Kingdom patent specifications 920,637, 940,051, 945,340 and 991,608 and in Belgian patent specification 648,710 as well as onium derivatives of amino-N-oxides as described in United Kingdom patent specification 1,121,696.

Among the stabilizers customarily employed in emulsions may be mentioned mercury compounds such as the mercury compounds described in Belgian patent specifications 524,121, 667,337 and 707,386, United States patent specification 3,179,520, heterocyclic nitrogen containing thioxo compuonds such as those described in German patent specification 1,151,731, benzothiazoline- 2-thione and 1 phenyl 2 tetrazoline 5 thione and compounds of the hydroxythiazolopyrimidine type such as 5-methyl-7-hydroxy-s-triazolo 1,5 pyrimidine.

The following illustrates the use of the combinations of sensitizers according to the invention.

Three types of emulsions were spectrally sensitized by means of a combination of sensitizers according to the present invention. These emulsion types are the following:

(A) An acid, double jet silver bromochloroiodide emulsion, prepared by the simultaneous addition from two separate jets of a solution of silver nitrate and a solution of a mixture of alkali halides to a gelatin solution comprising a little alkali halides; the emulsion contains 88.5 mole percent of silver bromide, 9 mole percent of silver chloride and 2.5 mole percent of silver iodide.

(B) An ammoniacal, double jet silver bromoiodide emulsion, prepared by the simultaneous addition from two separate jets of an ammoniacal silver nitrate solution and a mixture of halides to a gelatin solution; the emulsion comprises 95.3 mole percent of silver bromide and 4.7 mole percent of silver iodide, and

(C) An acid, silver bromoiodide emulsion, prepared by addition of a silver nitrate solution to a gelatin solution of a mixture of halides; the emulsion comprises 94 mole percent of silver bromide and 6 mole percent of silver iodide.

These three types of emulsions all comprise per mole of silver halide 1 g. of 5-methyl-7-hydroxy-s-triazole[1,5]- pyrimidine as stabilizer. The emulsions comprise per kg. about 0.3 mole of silver halide.

The emulsions are coated on a common support and dried. The emulsion layers are then exposed in a sensitometer through a step wedge with constant 0.15 and through a yellow filter (spectral sensitivity), the transmission of which for light of a wavelength shorter than 460 m is less than 0.1% and for light of a wavelength longer than 520 m is more than The relative spectral sensitivities obtained are listed in the table below as the number of measurable steps of the wedge used.

In the table below series of tests are listed for each type of emulsion. The particular combination of sensitizers used as well as the amounts of each sensitizer separately are also given.

EMULSION A Sensitlzer used Rhodaearboeyanine (I) Oarboeyanine(s) (II) MgJmole Spectral MgJmole of of silver sensi- Test No. silver halide N0. halide tivity 1.0 I/1 100 20.5 1.1.. I/l 100 11/1 132 21.5 1.2.. III 100 /2 132 20.5 1.3.. I/l 100 II/3 132 21 1.4 I/l 100 I1 4 132 1.5.. Ill 100 II/5 132 21 1.6.. U1 100 11/6 132 21 1.7.. 1/1 100 1I/7 132 20 1.8.. III 100 11/8 132 20 1.9.. III 100 II/9 132 20.5 1.10. I/l 100 11/10 132 21 1.11... Ill 100 II/11 132 21.5 1.12.- I/l 100 11/12 132 21.5 1.13... I/l 100 11/13 132 22 1.14.- I/l 100 11/14 132 21 1.15... I/l 100 132 21 1.16. I/l 100 11/16+II/17 (36/66 21 1.17. I/l 100 II 16+I1/1 66/66 21 1.18. I/l 100 11/16-1-11/18 66/66 22 1.19. III 100 1I/10-l-11/17 66/66 21 1.20. I/l 100 II/liH-II 66/66 21.5 1.21. Ill 100 II/19+I1/18 66/66 21.5

2.0 100 2. 100 11/1 132 20. 5 2. 100 11/2 132 20 2. 100 II/3 132 20 2. 100 11, 4 132 20 2. 100 11/5 132 20 2. 100 11/6 132 20 2. 100 II/7 132 21 2. 100 II/8 132 2. 100 II/Q 132 20 2. 100 11/10 132 20.5 2. 100 1I/11 132 20.5 2. 100 11/12 132 21 2. 100 II/13 132 20. 5 2. 106 11/14 132 19.5 2. 100 /l5 132 20.5 2. 100 11/16-1-11/17 66/66 20 2. 100 II/16+II/1 66/66 20 2. 100 1I/l6-l-II/l8 66/66 20 2. 100 11/19-1-11/17 66/66 21 2. 100 /19+11/1 66/66 20 2. 100 II/19+II/18 66/66 20. 5

3.0 100 18 3.1. 100 II/16+II/17 66/66 19. 5 3.2. 100 I1/16+I1/1 66/66 19. 5 3.3. 100 1I/16+I1/18 66/66 19.5 3.4 I/8 100 11/19+1I/17 66/66 19.5 3.5.. I/8 100 II/19+II/1 66/66 19.5 3.6 1/8 100 11/19-1-11/18 66/66 20 EMULSION B Rhodacarbocyanine (I) Mg./m0le Spectral Mg./mole of of silver sensi- Test No. silver halide N0. halide tivity 4.0 Ill 82 13 4.1.. III 82 I1/1 82 14 4.2 I/l 82 11/2 82 13 4.3 Ill 82 11/3 82 13.5 4.4 III 82 II/4 82 14 4.5 III 82 II/5 82 14 4.6 1/1 82 H/G 82 13 4.7 I/l 82 11/7 82 12. 5 4.8 Ill 82 II/8 82 12. 5 4.9 1/1 82 11/9 82 13.5 4.10- Ill 82 1I/10 82 14 4.11... Ill. 82 11/11 82 14 4.12-.. 1/1 82 11/12 82 14 4.13... Ill 82 II/13 82 14.5 4.14-.. 1/1. 82 11/15 82 14 4.15.-- 1/1 82 11/16-1-11/17 /50 14 4.16-.. Ill 82 II/16+II/1 50/50 14 4.17..- Ill 82 11/164-11/18 50/50 15 4.18-... Ill. 82 I1/19+I1/17 50/50 14.5 4.19-.. Ill 82 II/19+I1/1 50/50 14 4.20 Ill 82 11/10-1-11/18 50/50 14.5

5.0 1 3 82 82 13.3 5.1.. 82 II/l 82 13. 5 5.2.. 82 11/2 82 15 5.3.. 82 II/3 82 13.3 5.4.. 82 II/4 82 15 5.5.. 82 11/5 82 15 5.6.- 82 11/6 82 13 5.7.- 82 11/7 82 13.5 5.8 I/3 82 11/8 82 13 5.9 1/3 82 Il/U 82 13 EMULSION C MgJmole Spectra MgJmole of of silver sensi- Test No. silver halide No. halide tivity 6. 1/1 50 10.5 6. 1/1 50 11/1 100 13 6. I/l 50 11/2 100 12.5 6. 1/1 50 1I/3 100 13 6. 1/1 50 11/4 100 12 6. Ill 50 1I/5 100 12 6. 1/1 50 II/(i 100 11.5 6. 1/1 50 11/7 100 13.5 6. Ill 50 1I/8 100 12.5 6. I/1 50 11/9 100 13 6. Ill 50 II/lO 100 14 6. 1/1 50 11/11 100 13.5 6. l/l 50 11/12 100 13 6. Ill 50 II/13 100 14 6. 1/1 50 I1/14 100 13 6. Ill 50 11/15 100 13.5 6. 1/1 50 11/16-1-11/17 50/50 12.5 6. 1/1 50 11/16+I 1 50/50 13.5 6. 1/1 50 11/16+11/18 50/50 12.5 6. 1/1 50 11/19-1-11/17 50/50 13 6. Ill 50 11/19-1-11/1 50/50 14.5 6 Ill 50 II/10+1I/18 50/50 13.5

7.0 I/3 50 11. 5 7.1. 1/3 50 II/1 100 12 7.2. 1/3 50 I1/2 100 12 7.3- L3 50 II/3 100 12 7.4. I/3 50 11/4 100 11 7.5.-- 1/3 50 II/5 100 11.5 7.6 1/3 50 11/6 100 11 7.7-.. I/3 50 II/7 100 13 7.8 1/3 50 1I/8 100 12 7.9 I/3 50 11/10 100 13 7.10 1/3 50 1I/11 100 13 7.11 1/3 50 11/12 100 12.5 7.12 1/3 50 II/13 100 12 7.13 1/3 50 11/14 100 12 7.14 I/3 50 /l5 100 13 7.15 I/3 50 11/16-1-11/17 50/50 11.5 7.16 I/3 50 II/lG-HI/l 50/50 12 7.17 1/3 50 11/16-1-11/18 50/50 12 7.18 I/3 50 II/10+I1/17 50/50 12.6 7.19 I/3 50 11/19-1-11/1 50/50 12.5 7.20 1/3 50 1I/19+11/18 50/50 12.5

FIGS. 1 to 15 of the accompanying drawings graphically represent spectrograms of emulsions of tests 1.0, 1.3, 1.4, 1.7, 1.9, 1.10, 1.11, 1.12, 1.17, 1.21, 2.0, 2.3, 2.4, 2.8, 2.17, 2.21 respectively obtained in a spectrograph by exposure through a daylight compensating filter.

From these spectrograms it clearly appears that the sensitizers of the invention are completely compatible with each other, that all emulsions are uniformly sensitized up to 740 mm., that the gap in the green-yellow region of the spectrum is completely filled up and that the intensity of the sensitization practically does not vary with the wave length.

We claim:

1. Optically sensitized photographic light-sensitive material comprising in at least one silver halide emulsion layer a rhodacarbocyanine dye corresponding to the following general Formula I and at least one carbocyanine dye corresponding to the following general Formula II:

L is alkoxy or an amino group,

R is hydrogen, a lower alkyl group, a phenyl group or a benzyl group,

R is lower alkyl,

each of Z and Z represents the non-metallic atoms necessary to complete the same or dilferent thiazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, selenazole nucleus, benzoselenazole nucleus, or naphthoselenazole nucleus,

each of Q and Q is sulphur or selenium,

each of A and B is hydrogen, a fused aromatic ring, tetramethylene, methylene dioxy or one or more substituents selected from lower alkyl, phenyl, alkoxy, lower alkylthio, halogen and hydroxyl, and

X- is an anion when one of R and R does not contain an anionic group, said dyes being present in spectrally sensitizing amounts,

whereby the light sensitive material has a substantially uniform spectral sensitivity extending from the green to the extreme red or near infrared region of the spectrum.

2. Optically sensitized photographic light-sensitive material according to claim 1, wherein both the said rhodacarbocyanine and the said carbocyanine are present in the said silver halide emulsion layer(s) in amounts References Cited UNITED STATES PATENTS 2,647,052, 7/1953 Martin 96106 3,329,503 7/1967 Franke et a1. 96- -106 3,424,586 1/1969 Gotze 96106 FOREIGN PATENTS 837,674 6/1960 Great Britain.

WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US. Cl. X.R. 96-102, 104 

